This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. In this project, I plan to first examine the amyloid beta hypothesis of Alzheimer's disease (AD) and apply it to a novel Down Syndrome (DS) model by developing a mechanism in which the p3 fragment of the DS preamyloid can possibly be equivalent to the earliest stage of Alzheimer Disease, mild cognitive impairment (MCI). Secondly, by specifically focusing on glycolytic protein oxidation in this model, a basis for the reduced glucose metabolism observed in Alzheimer's disease may be determined and further support of the altered energy metabolism hypothesis of AD may be provided. Investigation of oxidatively modified glycolytic proteins in this novel DS model may also create a new focal point for potential biomarkers in AD and potential therapeutics. Down syndrome is a genetic disease in which persons have reduced mental capacity. Persons with DS have a trisomy at chromosome 21, the location of amyloid precursor protein. This trisomy causes A[unreadable] overproduction, which could possibly be a correlate to the early development of AD in persons with DS. Enzymatic cleavage by [unreadable]-secretase and [unreadable]-secretase forms the toxic p3 fragment, A[unreadable](17-42), which is the major form of A[unreadable] peptide in Down syndrome. No correlation has yet been made between the p3 fragment and AD pathogenesis. Glycolysis is a metabolic pathway that converts glucose to pyruvate and generates 2 ATP molecules in the process. Many key glycolytic enzymes such as [unreadable]-enolase, [unreadable]-enolase, glyceraldehyde 3-phosphate, phosphoglycerate mutase and triosephosphate isomerase are oxidized in AD brain confirming the inability to effectively metabolize glucose, the brain's principal source of energy. In the three progressive stages of Alzheimer's disease, MCI, EAD, and late-stage AD, 70% of glycolytic enzymes undergo oxidative modification, which can greatly affect their enzyme activity and subsequent protein function. All enzymes affected react after the production of fructose 1,6-bisphosphate (FBP). If oxidatively modified pre-FBP proteins are observed in DS, this will provide further support for the altered energy metabolism of AD.